Wall block



FIG. 1 is a top perspective view of a wall block;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front side elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a rear side elevational view thereof.

The broken lines in the figures depict portions of the wall block thatform no part of the claimed design.

CLAIM The ornamental design for a wall block, as shown and described.